2 Zotsatira zoyeserera ndi zokambirana
2.1Epitaxial wosanjikizamakulidwe ndi kufanana
Epitaxial wosanjikiza makulidwe, ndende ya doping ndi kufanana ndi chimodzi mwazozindikiro zapakatikati pakuwunika zamtundu wa epitaxial wafers. Kukula kolamulirika molondola, kukhazikika kwa doping ndi kufananiza mkati mwa chowotcha ndiye chinsinsi chowonetsetsa kuti magwiridwe antchito ndi osasinthika.Zida zamagetsi za SiC, ndi makulidwe a epitaxial wosanjikiza ndi kufanana kwa ndende ya doping ndizofunikiranso zoyezera luso la zida za epitaxial.
Chithunzi 3 chikuwonetsa makulidwe ofanana ndi kugawa kokhotakhota kwa 150 mm ndi 200 mmSiC epitaxial wafers. Zitha kuwoneka kuchokera pachithunzichi kuti epitaxial wosanjikiza makulidwe kagawo kagawo kagawo ndi ofanana pakatikati pa chowotcha. Epitaxial process nthawi ndi 600s, pafupifupi epitaxial wosanjikiza makulidwe a 150mm epitaxial wafer ndi 10.89 um, ndipo makulidwe ofanana ndi 1.05%. Powerengera, kuchuluka kwa epitaxial kukula ndi 65.3 um/h, yomwe ndi njira yofulumira ya epitaxial process. Pansi pa nthawi yomweyo ya epitaxial process, makulidwe a epitaxial layer ya 200 mm epitaxial wafer ndi 10.10 um, makulidwe ofanana ali mkati mwa 1.36%, ndipo kukula konse ndi 60.60 um / h, komwe kumakhala kotsika pang'ono kuposa kukula kwa 150 mm epitaxial. mlingo. Ichi ndi chifukwa pali zoonekeratu imfa panjira pamene pakachitsulo gwero ndi mpweya gwero zikuyenda kuchokera kumtunda kwa chipinda anachita mwa chophwanyika pamwamba pa mtsinje wa kunsi kwa chipinda anachita, ndi 200 mm yopyapyala dera lalikulu kuposa 150 mm. Mpweya umayenda pamwamba pa chowotcha cha 200 mm kwa mtunda wautali, ndipo gwero la gasi lomwe limagwiritsidwa ntchito panjira ndi lochulukirapo. Pansi pa chiwongolero chakuti chophikacho chimayenda mozungulira, makulidwe onse a epitaxial wosanjikiza amakhala ochepa kwambiri, kotero kuti kukula kwake kumakhala pang'onopang'ono. Ponseponse, makulidwe ofanana a 150 mm ndi 200 mm epitaxial wafers ndiabwino kwambiri, komanso kuthekera kwa zidazo kumatha kukwaniritsa zofunikira za zida zapamwamba.
2.2 Epitaxial wosanjikiza doping ndende ndi kufanana
Chithunzi 4 chikuwonetsa kufanana kwa ndende ya doping ndi kugawa kopindika kwa 150 mm ndi 200 mmSiC epitaxial wafers. Monga momwe tikuwonera pachithunzichi, njira yogawa ndende pa epitaxial wafer imakhala yofananira yofananira pakati pa mtanda. The doping ndende uniformity wa 150 mm ndi 200 mm epitaxial zigawo ndi 2.80% ndi 2.66% motero, amene akhoza kulamuliridwa mkati 3%, umene ndi mlingo wabwino kwambiri kwa zipangizo zofanana mayiko. Doping ndende yokhotakhota wa epitaxial wosanjikiza anagawira "W" mawonekedwe m'mimba mwake, amene makamaka anatsimikiza ndi otaya yopingasa yotentha khoma ng'anjo ya epitaxial, chifukwa mpweya wodutsa njira yopingasa airflow epitaxial kukula ng'anjo amachokera. mpweya wolowera kumtunda (kumtunda) ndipo umayenda kuchokera kumapeto kwa mtsinjewo mopanda malire kudutsa pamwamba pake; chifukwa "kuchepa kwapanjira" mlingo wa carbon source (C2H4) ndi wapamwamba kusiyana ndi gwero la silicon (TCS), pamene chophika chimazungulira, C / Si yeniyeni pamtunda wophika pang'onopang'ono imatsika pang'onopang'ono kuchokera m'mphepete kupita. pakatikati (gwero la kaboni pakatikati ndi locheperako), malinga ndi "lingaliro lopikisana" la C ndi N, ndende ya doping yomwe ili pakatikati pa mtanda imatsika pang'onopang'ono mpaka m'mphepete, kuti mupeze ndende yabwino kwambiri. kufanana, m'mphepete N2 anawonjezera monga chipukuta misozi pa ndondomeko epitaxial kuchepetsa kuchepa doping ndende kuchokera pakati mpaka m'mphepete, kotero kuti yomaliza doping ndende pamapindikira amapereka "W" mawonekedwe.
2.3 Zowonongeka za Epitaxial layer
Kuphatikiza pa makulidwe ndi ndende ya doping, mulingo wa epitaxial wosanjikiza chiwongolero ndi gawo lofunikira poyezera mtundu wa zowotcha za epitaxial komanso chizindikiro chofunikira cha kuthekera kwa zida za epitaxial. Ngakhale SBD ndi MOSFET ali ndi zofunika zosiyana pa zilema, zoonekeratu pamwamba morphology chilema monga dontho chilema, makona atatu, kaloti zolakwika, comet defect, etc. amatanthauzidwa ngati kupha chilema cha SBD ndi MOSFET zipangizo. Kuthekera kwa kulephera kwa tchipisi zomwe zili ndi zolakwikazi ndizokwera, kotero kuwongolera kuchuluka kwa zolakwika zakupha ndikofunikira kwambiri pakuwongolera zokolola za chip ndikuchepetsa mtengo. Chithunzi 5 chikuwonetsa kugawidwa kwa zilema zakupha za 150 mm ndi 200 mm SiC epitaxial wafers. Pansi pa chikhalidwe chakuti palibe kusalinganika koonekeratu mu chiŵerengero cha C / Si, zolakwika za karoti ndi zofooka za comet zikhoza kuthetsedwa, pamene zofooka za dontho ndi makona atatu zimagwirizana ndi kulamulira kwaukhondo panthawi yogwiritsira ntchito zida za epitaxial, mlingo wonyansa wa graphite. mbali mu chipinda anachita, ndi khalidwe la gawo lapansi. Kuchokera pa Table 2, zikhoza kuwoneka kuti kachulukidwe wakupha wa 150 mm ndi 200 mm epitaxial wafers akhoza kuwongoleredwa mkati mwa 0.3 particles / cm2, yomwe ndi mlingo wabwino kwambiri wa zipangizo zamtundu womwewo. The fatal defect density control level of 150 mm epitaxial wafer ndi yabwino kuposa 200 mm epitaxial wafer. Ichi ndi chifukwa gawo lapansi kukonzekera ndondomeko 150 mm ndi okhwima kuposa 200 mm, gawo lapansi khalidwe bwino, ndi kulamulira zonyansa mlingo wa 150 mm graphite anachita chipinda bwino.
2.4 Epitaxial wafer pamwamba pa roughness
Chithunzi 6 chikuwonetsa zithunzi za AFM pamtunda wa 150 mm ndi 200 mm SiC epitaxial wafers. Zitha kuwoneka kuchokera pazithunzi kuti mizu ya pamwamba imatanthawuza roughness ya 150 mm ndi 200 mm epitaxial wafers ndi 0,129 nm ndi 0,113 nm motero, ndipo pamwamba pa epitaxial wosanjikiza ndi yosalala popanda chodziwika chachikulu-step aggregation chodabwitsa. Chodabwitsa ichi chikuwonetsa kuti kukula kwa epitaxial wosanjikiza nthawi zonse kumasunga njira yakukula kwa sitepe panthawi yonse ya epitaxial, ndipo palibe kuphatikizika kwa sitepe kumachitika. Zitha kuwoneka kuti pogwiritsa ntchito njira yowonjezereka ya kukula kwa epitaxial, zigawo zosalala za epitaxial zitha kupezeka pa 150 mm ndi 200 mm low-angle substrates.
3 Mapeto
150 mm ndi 200 mm 4H-SiC homogeneous epitaxial wafers adakonzedwa bwino pazigawo zapakhomo pogwiritsa ntchito zida zodzipangira zokha za 200 mm SiC epitaxial kukula, ndipo njira yofanana ya epitaxial yoyenera 150 mm ndi 200 mm idapangidwa. Kukula kwa epitaxial kumatha kukhala kwakukulu kuposa 60 μm/h. Pokwaniritsa zofunikira za epitaxy zothamanga kwambiri, mtundu wa epitaxial wafer ndi wabwino kwambiri. Makulidwe ofanana a 150 mm ndi 200 mm SiC epitaxial wafers amatha kuwongoleredwa mkati mwa 1.5%, ndende yofananira ndi yochepera 3%, kachulukidwe wakupha ndi wosakwana 0.3 particles/cm2, ndipo epitaxial surface roughness root mean square Ra ndi zosakwana 0.15 nm. Zizindikiro zazikuluzikulu za ma epitaxial wafers zili pamlingo wapamwamba kwambiri pamsika.
Gwero: Zida Zapadera za Electronic Industry Special Equipment
Wolemba: Xie Tianle, Li Ping, Yang Yu, Gong Xiaoliang, Ba Sai, Chen Guoqin, Wan Shengqiang
(48th Research Institute of China Electronics Technology Group Corporation, Changsha, Hunan 410111)
Nthawi yotumiza: Sep-04-2024